Skid jack for mobile homes

ABSTRACT

This is a skid jack for mobile or trailer homes. It consists of a substantially rectangular frame having mobility provided by a pair of castor wheels and a pair of power wheels on an axle having a slip clutch so that it can be steered. The entire jack as assembled is of substantial size, weighing about 1,800 or 2,000 pounds. The wheels are only for providing mobility in properly positioning the jack under the mobile home, and are retracted so that the frame is based on the ground directly. Hydraulic power means is provided for the various operations, including powering the wheels, lifting a support rail against the bottom of a mobile home to lift it up, skidding the supported mobile home up to twelve inches at a time. Separately controlled hydraulic means are provided for lifting, supporting and lowering each end of the support rail. The procedure is repeated often as necessary according to the distance it must be moved. The castor wheels may be latched against castoring to move the jack in a straight line. A separate hydraulic cylinder is provided for raising or lowering the four wheels simultaneously, another cylinder for skidding the support rail, another for lifting one side, another for lifting the other side and hydraulic means are provided for power in the wheels. A separate valve is provided for each cylinder, the valve being controllable for operating in both directions, as well as for locking the part against operation.

Unite States Patent 1 3,840,210

Hollingsworth Oct. 8, 1974 1 SKID JACK FOR MOBILE HOMES sists of a substantially rectangular frame having mobil- [76] Inventor: Richard L. Hollingsworth, 105 Provided by a Pair of Wheels and a Pair 9 Watson Ave shrewsbury W Va. power wheels on an axle having a slip clutch so that it 25184 can be steered. The entire ack as assembled 15 of substantial size, weighing about 1,800 or 2,000 pounds.

[ 1 Filed: June 5, 1973 The wheels are only for providing mobility in properly positioning the jack under the mobile home, and are [21] Appl' 367l37 retracted so that the frame is based on the ground directly. Hydraulic power means is provided for the var- 1 Cl 254/9 80/4323 ious operations, including powering the wheels, lifting [51] Int. Cl B66f 11/04 a support rail against the bottom of a mobile home to [58 Field of Search 254/9 R, 9 B, 9 C, 84, lift it up, skidding the supported mobile home up to 280/4 twelve inches at a time. Separately controlled hydrau- /1 l 238/13 lic means are provided for lifting, supporting and lowering each end of the support rail.

[56] References The procedure is repeated often as necessary UNITED STATES PATENTS according to the distance it must be moved. The

2,471.901 5/l949 Ross 254/89 castor wheels may be latched against castoring to 2,896,909 7/l959 Taylor 254/9 R move the jack in a straight line. A separate hydraulic 2,929,519 3/1960 Taylor r 214/1 D ylinder is provided for raising o lowering the four 293L519 4/1960 Beach t 214/ wheels simultaneously, another cylinder for skidding 3,544,127 12/1970 Dobson 280/4117 Primary Examiner-Al Lawrence Smith Assistant Examiner-Robert C. Watson Attorney, Agent, or Firm-Gustave Miller [57] ABSTRACT This is a skid jack for mobile or trailer homes. It conthe support rail, another for lifting one side, another for lifting the other side and hydraulic means are provided for power in the wheels. A separate valve is provided for each cylinder, the valve being controllable for operating in both directions, as well as for locking the part against operation.

9 Claims, 9 Drawing Figures PATENTED 8 I974 SHEET 8 0F 6 Q m mm; in u mm mm km 0 QQ\ 0 \N R \mw mm o 0 W mw/ Q 4 Z |||W1IM|M|1 Q mm. o IMIIIIHIIHIHIHHIIHHIHI: 1 u I I. o w wn wl l l l n lmml 1. mm mm a wm R mm 1 0 mm 1 0 mm q mm k. m 6Q SKID JACK FOR MOBILE HOMES BACKGROUND OF THE INVENTION Mobile homes or trailer homes are being built bigger and bigger, both in length and width, sometimes being made in two longitudinal portions, up to 75 feet in length and 14 feet in width, especially when in two pieces. Such large mobile homes or halves thereof must be transported over highways and then often over winding, narrow roads, with curves too sharp for the mobile home to be towed around the curves, or around sharp corners. Then, at the destination, the mobile home must be maneuvered onto the mobile home site, often a question of moving them laterally, there being no possibility of moving them longitudinally. At present, this is handled by a tow truck, placing greased panels under the mobile home, and pushing or pulling thereagainst, always with extensive damage to the moverely tying up traffic on the narrow highways.

OBJECTS OF THE INVENTION It is an object of this invention to provide a skid jack capable of safely maneuvering large mobile homes or the like in very limited areas, such as on narrow curved or Winding highways, or in positioning the trailer or mobile home into its permanent location.

A further object of this invention is to provide a skid jack capable of maneuvering all sizes of mobile homes, particularly the very large sizes, to move or skid them around corners or into position when positioning the mobile home into its permanent location.

Still, a further object of this invention is to provide a skid jack that can lift a mobile home and move it a step at a time, up to twelve inches per step, to move it either in a desired direction or to position it as desired.

A further object of this invention is to provide a skid jack capable of moving or rather skidding a very heavy, large load a short distance at a time without damage to the load.

A further object is to provide a skid jack that is mobile and self-contained.

A further object of this invention is to provide a skid jack that rests its base firmly on the ground when jacking up the load and skidding the load, and that has powered and castored wheels that are extendible for mobility and retractable for jack operation.

A further object of this invention is to provide an improvement over prior art jacks such as illustrated in U.S. Pat. Nos. 2,535,221; 2,471,901; 2,896,909; and 2,929,519, amongst others.

BRIEF DESCRIPTION OF FIGURES With the above and related objects in view, this invention consists in the details of construction and combination of parts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation showing both the lifting rail in elevated position and the wheels in extended position, for economy of drawing. In actual operation, the wheels are retracted while the rail is being elevated, held up or being lowered. The top rail is kept in lowered position when the wheels are extended for moving or positioning the entire skid jack, as in FIG. 2.

FIG. 2 shows the skid jack with the top rail in lowered position and the wheels in extended position for moving the skid jack about to properly position it, the hydraulic power system being omitted for clarity.

FIG. 3 is an enlarged view, partly in section, showing the details of one of the movable top and bottom shoes and of the skid plate.

FIG. 4 is a framentary end view on line 4-4 of FIG. 3.

FIG. 5 shows the jack in full lines as positioned under a mobile home, and in dotted lines with the top rail in elevated position for lifting a mobile home for skidding 11.

FIG. 6 is an enlarged transverse sectional view on line 66 of FIG. 1.

FIG. 7 is a top plan view of the rectangular frame and skid channel member.

FIG. 8 is a shematic plan of the operating hydraulic mechanism and drive motor.

FIG. 9 is a perspective view of the frame and skid channel member of FIG. 7 with some additional details.

There is shown at 9 the skid jack of this invention for skidding or positioning mobile homes. As an assembled whole, it usually weighs about 1,800 to 2,000 pounds. Lifting jack 9 includes a substantially rectangular base frame. It is made up of end, side and transverse heavy angle iron members providing a rigid frame'as apparent in FIGS. 7 and 9. Extending from one transverse angle iron member 291 across the other two intermediate angle iron members and the end angle iron member 292 longitudinally of the center line is a bottom skid channel plate 13, the inside of which is kept well greased at 131 in operation. A skid channel member 11 may be skidded or moved in the skid channel plate 13, up to a distance of approximately 12 inches, as far as position 10. The bottom skid channel plate 13 is approximately 8 feet long. These and other dimensions mentioned'here and elsewhere in this specification are that of a full size jack that has been constructed and operated, and are mentioned to show approximate proportions of the various details.

Guide bars 89 (see FIGS. 3 and 6) are welded to the inner sides of the sidewalls of skid channel plate 13 and cooperate with laterally extending webs 111 of skid 11 to retain the skid 11 slidably in position within skid channel plate 13. Similar guide bars on the inner side walls of channel skid l1 cooperate with webs 141 of left and right bottom travel shoes 14 and 15, each of which are independently movable a distance of approximately 10 inches on a coating of grease on the inner bottom of channel skid ll.

Clevis eyes 34 and 35 on bottom travel shoes 14 and 15 receive one inch clevis pins 40 and 41 on which are pivoted left and right pusher rods 36 and 37 for controllably lifting, supporting and lowering either or both ends of the inverted channel to rail 48. This top rail 48 is about 8 feet long, being about three inches lower at each end in order to keep the height of the jack 9 as low as possible. Fixedly straddling these lowered ends of rail 48 are lifting brackets 49 and 50 for cooperating with left and right bottom beams 491 and 501 of mobile home H being transported and positioned.

The top ends of pusher rods 36 and 37 are pivotally connected by one inch clevis pins 66 and 67 to knee portions 101 of right and left lifting linkage rods 38 and 39. These knee portions 101 are in turn pivotally connected by one inch clevis pins 70 to clevis eyes 69 extending downwardly from left and right upper travel shoes 68. These upper travel shoes 68 are slidable about 7 inches in the inverted bottom ends of rail 48, being slidably retained therein by guide bars 71 extend ing the length of the lower end portions of top rail 48 and are well greased.

The bottom ends of lifting linkage rods 38 and 39 are each pivotally connected by clevis pins 61 and 62 respectively to left and right lifting linkage rod base posts 46 dnd 47, each welded to the skid member 11. Also pivotally connected to these same linkage rod base posts 46 and 47 by the same clevis pins 61 and 62 are two pairs of pivotally connected stabilizer bars 42 and 43, and 44 and 45, the longer stabilizer bars 42 and 44 being pivoted to the base posts 46 and 47, the shorter bars 43 and 45 being each respectively pinned by clevis pins to clevis eyes 64 (see FIG. 4) integrally depending from brackets 49 and 50 at the ends of top rail 48.

The base posts 46 and 47 are each welded at their bottom ends to the skid channel member 11. Base post 46 is abutted by skid cylinder 12, and the piston rod 121 of cylinder 12 is pivoted by clevis pin 65 to base post 52. Base post 52 is welded to the side of skid channel plate 13, and thus fixed relative to the frame 29. No cylinder is needed or provided for the right base post 47 because it also is fixed to skid 11 and is thus fixed relative to the left base post 46.

Left travel shoe 14 is independently actuated by cylinder 16 and its cylinder rod 161, cylinder 16 being pinned and abutted at eye 16' to bracket 96 fixed on skid 11. Right travel shoe is similarly actuated by right cylinder 17, pinned and abutted by the same.

bracket 96 at eye 17', the piston rod 171 of cylinder 17 being pinned to right travel shoe 15.

Mobility for the jack 9, for positioning it, is provided by a pair of powered wheels 18 and a pair of castor wheels 19, which may be simultaneously extended below the jack 9 or entirely retracted by having their power wheel forks 20 and castor wheel forks 21 connected together by a tie rod 27 and actuated, that is, raised or lowered, by cylinder 26 and piston rod 261, operating details of which follow,

The back or castor wheels 19 have their axles 23 in castor forks 21. These castor forks 21 are vertically pivoted at 99 for castor movement in a pillow block 100. A latch 97 and latch spring 98 may be manually operated to latch or release the castor fork 21 for castor movement relative to pillow block 100. The pillow block 100 in turn is securedly fastened on cross shaft 33, which is journaled on a bearing 31 fixed on frame 29 for 90 rotation by actuating arm 32 fixed thereto for thus raising or lowering all the wheels. This actuating arm 32 is operated by being pivoted to the tie rods 27 whose other ends are pivoted by one inch clevis pins 63 to front or power wheels fork angular arm as well as to tie rods 27.

The arm 30 is an angular arm integrally extending from the top of fork 20 so as to raise or lower front power wheels 18 simultaneously with the back castor wheels 19. The raising or lowering is done by the wheel lowering and raising cylinder 26 and its piston rod 261 pivoted by clevis pin 63 to arm 30. Cylinder 26 is abutted and pivoted to base bracket 28, which is fixed to frame 29. The piston rod 261 has its outer end pivoted on the angular arm 30 of front wheel forks 20 and thus controls and actuates the tie rod 27, thereby controlling the lifting and lowering of the front power wheels 18 and the back castor wheels 19.

As shown in FIG. 9, a series of controls 58 are provided for each of the four cylinders 12, 16, 17 and 26, consisting of hydraulic valves, as in FIG. 8 valve 112 for skid cylinder 12, valve 116 for left shoe cylinder 16, valve 117 for right shoe cylinder shoe 17, and valve 126 for wheel lowering and raising cylinder 26. A fifth hydraulic valve 174 is provided for hydraulically operating the hydraulic motor 74 that powers the wheels 18 in either direction. As shown in section for the hydraulic valve 117, all the valves can direct the hydraulic pressure fluid in either direction, as well as for cutting off and locking the pressure fluid in place.

The hydraulic fluid is provided by a pump P run by a gasoline engine 59 and the pressure fluid travels through each of the valves as called for by their setting and then goes to the reservoir tank T and back to the pump P, as needed. The gasoline engine 59, pump P, gasoline tank 60, reservoir tank T and other incidental operating mechanism are located in area 91 on the frame 29 between the cross angle iron 291 and the end of the frame and between the brace arms 56 and hydraulic control panel bar 94 on an upright support post 55, to which is connected the handle bar 57 for manually steering the jack 9.

The hydraulic valves are physically located in the area 92 and are operated by remote control by the hy draulic control members 58. Openings 93 in the frame 29 are wells for receiving and storing the retracted power wheels 18, while the castor wheels 19 are retracted outside the frame 29 but adjacent the area 91.

The mechanism for powering the wheels 18 is shown in more detail in FIG. 6. The wheels 18 are journaled I on axles 22 in the forks 20. A sprocket 87 is secured within the fork 20 on each wheel 18, and a sprocket chain 86 connects the wheel sprocket 87 to shaft sprocket or 81 in power wheel assembly 77, the left sprocket chain 86 connecting to sprocket 75 and the right sprocket chain 86 connecting to shaft sprocket 81. Both shaft sprockets 75 and 81 are powered by a drive shaft 24 journaled inside roller bearings 95, the assembly 77 being also journaled on the outside of bearings 95 and inside bearing blocks 25 supported at 88 on frame 29.

The hydraulic motor 74 is mounted in a bracket 53 and the motor shaft of motor 74 has a sprocket 54 connected by sprocket chain 72 to a sprocket wheel 73 fixed on drive shaft 24 for rotating the drive shaft 24 and thus supplying power to the drive shaft 24. The drive shaft 24 in the assembly 77 includes a slip clutch assembly 76 consisting of a serrated clutch face 78 integrally united to the shaft 24, and a second serrated clutch face 79on a spacer member 80 journaled on and axiallyslidable on the power shaft 24 and having the sprocket 81 integrally secured thereto. The spacer 80, sprocket 81, and its clutch face 79, are yieldably urged into clutching contact with clutch face 78 by a spring 82 biased thereagainst by a washer 83 adjusted by a nut 84 and locked in adjusted position by a lock nut 85, both threaded on the end of shaft 24. The clutch faces being serrated, their tapered saw-like teeth will slip away from each other whenever back or forward pressure on either one wheel is greater or less than on the other wheel, thus permitting the wheels to rotate at different speeds in either direction.

The shaft 24 will deliver power to both wheels 18 equally as long as no side pressure is applied manually by the manually held and controlled steering handle 57. However, when it is desired to turn the direction of the jack in either direction, appropriate side pressure is manually applied to handle 57 so that one wheel 18 will have to turn faster or slower than the other. The back or forward pressure from the right wheel 18 (as viewed in FIG. 6) along its sprocket chain 86 will cause the serrated clutch face 79 to move axially against the spring 82 and slip away from the fixed serrated clutch face 78 on shaft 24, the serrated teeth being saw-like or tapered thus permitting the two wheels 18 to operate at different speeds to make a turn in either direction.

OPERATION OF THE INVENTION When the jack is being raised, the wheels 18 and 19 are first lowered or extended by control valve 126 receiving and directing hydraulic fluid from pump P (being in operation from the engine 59). With the wheels fully extended, the valve 174 is adjusted to lock When the jack 9 is at the point to be placed under the mobile home H, latch pin 97 is actuated to lock the eastor wheels 19 against castoring. With the top rail 48 in lowered position, the wheels 19 and 20 are lifted from the fully extended position to a position contacting the ground just an inch or two below the frame 29, just below the position illustrated in FIG. 5, enough for the wheels 18 and 19 to have good frictional contact with the ground. In this position, the jack 9 is only 13 or 14 inches high, and it can be readily maneuvered under a mobile home H. Then, when the jack 9 is thus manervered into the proper position, the rail 48 may be raised enough to verify that the lifting brackets 49 and 50 are properly positioned to mobile home supporting beams 491 and 501. Then, when valve 126 is operated, it retracts all the wheels, lowering the jack so that it rests and is based on the ground therebeneath. Next, the valves 116 and 117 are operated independently but simultaneously to lift both ends of the rail 48 if on level ground. If the ground is slightly uneven, the lower end may be raised to make the home level, or it may be deliberately placed at an angle as desired. The home H may be raised as much as thirty inches if needed. Then, while valves 116 and 117 are placed in jack supporting position, valve 112 is actuated to skid or transversely move the skid 11, the rail 48 and home H, as desired, up to a maximum distance of twelve inches to positions 10 and 51. If more distance is needed, the rail 48 is lowered, and the procedure is repeated to reposition the jack 9, then the rail 48 is again raised after repositioning the skid l1, and the entire procedure may be repeated as often as necessary. Either side of the mobile home H may be lifted independently by either control valve 116m 117 to hold one side up, as for changing a tire on the mobile home, or for changing the angle level of the home H, as may be necessary or desired. The mobile home H may be similarly manipulated on a narrow highway to take it around a corner without damaging it, much more quickly and safely than with present methods of using tow truck and greased panels.

ABSTRACT OF THE DRAWINGS In the drawings, like numbers refer to like parts, and for the purpose of explication, set forth below are the numbers part of the improved MOBILE HOME JACK of this invention.

9 jack 10 set over or extended position of skid 11 11 channel shaped skid member, 8 feet long, greased on both inside and bottom side 12 skid operating cylinder 13 channel shaped skid plate in which skid 11 is reciprocable to a maximum of 12 inches up to position 10 14 left bottom travel shoe, slidable in skid :11

15 right bottom travel shoe in skid 11 16 left travel shoe cylinder abutting against bracket 16' left clevis pin eye in96 a right travel shoe cylinder abutting against bracket 96 at 17' I I 17' right clevis pin eye in 96 18 front powered wheels, retractable and extendable l9 castored back wheels, retractable and extendable 20 front wheel forks 21 castored back wheel forks 22 one inch axlesin forks 20 for wheels 18 23 one inch axles in forks 21 for wheels 19 24 front wheel assembly power shaft 25 front wheel pillow type bearing block 26 wheels lowering and raising cylinder 27 tie rod connecting all wheels for simultaneous lowering and raising operation. A

28 mounting base bracket for wheel cylinder 26 29 main frame, rectangular in outline 30 integrally extending angular arm of forks 20 and pivoted to cylinder 26, and also to tie rod 27 31 pillow type bearing block secured on frame 29 for cross axle 33 32 upright arm on 33 33 cross axle for connecting both castor forks 21 34 left clevis eye member welded to left travel shoe 35 right clevis eye member welded to right travel shoe 14 36 left pusher rod that lifts left end of top rail 48. It is pivoted by clevis pin 66 to knee portion 101 of left lifting linkage 38 and at bottom to clevis pin of left travel shoe 14 37 right pusher rod, operates same as 36 on other side 38 left lifting linkage rod, at top end pivoted by clevis pin to clevis eye 69 of left top travel shoe 68 39 right lifting linkage rod, on right side similar to 38 41 clevis pin on right side similar function as left clevis pin 42 left long stabilizer bar, pivoted at bottom by clevis pin M to base post 46 43 left short stabilizer bar, pivotally connected at bottom to top of long left stabilizer bar 42 and at top to lifting bracket 49 44 long right stabilizer bar 45 short right stabilizer bar. 44 and 45 function same as 42 and 43.

46 left lifting linkage rod base post, welded at bottom to skid 11 and is a base post for butt end of skid cylinder 12, to push or pull skid 11 47 right lifting linkage rod base post, same as 46, but

no cylinder is attached 48 load support top rail, 8 feet long, dropped at each end 3 inches, keeping as low as possible the height of jack 49 left load lifting bracket straddling left end of rail 48, about 14 inches long a 50 right lifting load bracket on 45, similar to 49 51 dotted lines showing left limit of' travel of 48,

above position 10 of skid 11 52 base post for piston rod 121 welded to side of skid plate 13 53 bracket for housing hydraulic motor 74 54 sprocket on shaft of hydraulic motor 74 55 steering handle bar support post 56 angle brace arms for 55 57 handle bar for steering jack 9 58 controls for hydraulic valves 59 gasoline engine 60 gasoline tank 61 one inch clevis pin, pivotally connects left lifting linkage rod 38, stabilizer lower bar 42, butt end of skid cylinder 12 and left linkage rod base post 46.

' 62 clevis pin on right side, similar function to 61,but

no cylinder 63 clevis pin pivotally connecting front wheel fork arm 30, tie rod 27 for all four wheels and piston rod 261 64 pair of depending clevis eyes secured to mobile home lifting bracket 49 and pivotally pinned to short stabilizer bar 43 65 clevis pin pivotally connecting piston rod 121 of skid cylinder 12 to base post 52 66 left clevis pin pivotally connecting left pusher rod 36 and knee portion 101 of left lifting linkage rod 67 clevis pin on right, similar function to 66 68 left top travel shoe, travels about seven inches and must be well greased 69 depending clevis eye welded to travel shoe 68 70 left end clevis pin providing pintle joint to left travel shoe clevis eye 69 and knee portion 101 of left linkage rod 38 71 guide bars or tracks for top travel shoe 68 in depending side walls of rail 48 72 sprocket chain on sprocket 54 of motor 74 73 sprocket fixed on wheel power shaft 24 74 hydraulic motor for operating wheels 18 75 sprocket fixed on shaft 24 to operate wheels 18 76 slip clutch assembly for power shaft 24 77 power wheel assembly to which power wheel forks 20 are attached for ninety degree extending and retracting motion within pillow type bearing blocks 25 78 serrated slip clutch face fixed to shaft 24 79 slip clutch face fixed to spacer 80 and both journaled as a unit on shaft 24 80 clutch spacer 81 sprocket fixed to clutch spacer 80 82 clutch face pusher spring 83 washer between 82 and 84 84 clutch spring adjusting nut 85 lock nut for nut 84 86 sprocket chain to wheel sprockets 87 from 75 or 87 wheel sprockets 88 support on frame 29 for power shaft pillow type bearing blocks 25 89 guide bars on side of bottom skid plate 13 slidably holding skid 11 90 guide bars about 16 inches long on both inner sides of both ends of 11, cooperating with bottom travel shoe wings 141 holding bottom travel shoes 14 slidably in position in greased skid 11 91 area location of engine and pressure tank 92 area location of hydraulic valves 93 wells for retracting power 'wheels 18 94 shaft supporting hydraulic controls 95 roller bearings in pillow blocks 25 for power shaft 24 ends of 77 96 base abuttment for shoe cylinders 16 and 17 97 spring loaded latch for castor forks 21 98 spring in 97 99 vertical pivot for castor forks 21 100 castor fork pillow block secured to cross axle 33 101 knee portion of lifting linkages 38, 39

111 extending webs of skid ll 112 skid cylinder valve 116 left shoe cylinder valve 117 right shoe cylinder valve 121 skid cylinder piston rod 126 wheel lowering and lifting cylinder valve 131 grease sheath in frame channel skid plate member 13 1 141 extending wings of left travel shoe 14 161 left shoe cylinder piston rod 171 right shoe cylinder piston rod 174 hydraulic valve to motor 74 261 piston rod of cylinder 26 291 transverse angle iron members 292 end transverse angle iron member 491 mobile home left support beam 501 mobile home right support beam H mobile home P hydraulic pressure pump T hydraulic pressure fluid reservoir tank M motor 74 Although this invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied within the scope of what is claimed.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

1. A skid jack (9) for mobile homes and the like, said jack (9) comprising a rectangular frame (29), a chan nel member (11) slidably reciprocable within said frame channel member (13), an inverted channel load support rail (48), a slidable top travel shoe (68) extending into each bottom end of said inverted channel rail (48), means (71) slidably retaining said slidable top shoes (68) in position in said rail (48), each top travel shoe (68) having depending clevis eye means (69), a lifting linkage rod member (38 or 39) having a knee portion (101), a clevis pin (70) pivotally securing said knee portion (101) to said depending clevis eye means (69), a second clevis pin (61 or 62) pivotally securing the bottom end of said lifting linkage rod (38) to a base post (46 or 47) fixedly secured to said skid member (11), a pusher rod (36 or 37) pivotally secured by clevis pin means (66 or 67) at its top end to said depending clevis eye means (69) of said top slidable travel shoe (68) and at its bottom end by a clevis pin (40 or 41) to an upwardly extending clevis eye means (34 or 35) ofa travel shoe (14 or 15), means (90, 114) slidably retaining said bottom travel shoe (14) in said skid channel member (11), means (89, 111) slidably retaining said skid channel member (11) in said rigid channel member (13), knee-jointed stabilizer legs (42, 43 or 44, 45) pivotally (61 or 62) secured to each said base posts (46 or 47) and to said inverted channel top load-support rail (48), a base post (52) fixed relative to said frame (29), push and pull means (12) operatively biased between said fixed base post (52) and one said skid base post (46) for controllably sliding said skid channel member (11) within said rigid channel member (13), and separate push and pull means (16 or 17) for each lower travel shoe biased thereagainst and against a base abutment (96) fixed relative to said skid 11 for controllably raising, holding and lowering said load-support rail, and skid jack wheel means (18, 19) retractable relative to and extendable below said frame (29) providing mobility for said jack (9).

2. The skid jack of claim 1, said means for slidably retaining said slidable top and bottom travel shoes and within said respective channel members (48, 11) and cooperating webs (141 and 111) on said travel shoes (14 and 15) and on said skid channel member (11).

3. The skid jack of claim 2, said lower travel shoe retainer guide bars (90) within saidskid channel member (11) being spaced from the bottom thereof, said skid channel member retainer guide bars (89) within said base channel member (13) being spaced from the inside bottom thereof and said upper travel shoe retainer guide bars (71) being secured to depending side walls from said load support rail (48).

4. The skid jack of claim 1, said push and pull means comprising hydraulic cylinder (12) and piston means (121).

5. The skid jack of claim 1, said wheel means including a pair of power receiving wheels (18), a power axle (24) providing rotary power to each wheel, a slip clutch assembly (76) in said power axle (24) providing rotary power to each wheel, a slip clutch assembly (76) in said power axle, and a power motor (74) for said axle.

6. The skid jack of claim 1, said wheel means including two pairs of forks (20, 21) having wheel mounting axles ('22, 23) and wheels (18, 19), said forms (20, 21) being pivoted for retracting or extending said wheels (18, 19), tie means (27) securing said forks (20, 21) together for simultaneous retracting or extending movement, and controllable piston (261) and cylinder (26) means biased between said tie means (27) and said frame (29) for retracting or extending said wheels (18, 19).

7. The skid jack of claim 6, one pair of wheel forks (121) being vertically pivoted and castored.

8. The skid jack of claim 7, and latch means (97) for securing said vertically pivoted forks (21) against castormg.

9. The skid jack of claim 8, and power means (74) operatively connected to one pair of forked wheels (18) providing the powered mobility to said skid jack said skid channel member in their respective channel (9).

members comprising guide bars (71, 90) secured 

1. A skid jack (9) for mobile homes and the like, said jack (9) comprising a rectangular frame (29), a channel member (13) rigidly fixed on said frame along the approximate elongate central line thereof, a skid channel member (11) slidably reciprocable within said frame channel member (13), an inverted channel load support rail (48), a slidable top travel shoe (68) extending into each bottom end of said inverted channel rail (48), means (71) slidably retaining said slidable top shoes (68) in position in said rail (48), each top travel shoe (68) having depending clevis eye means (69), a lifting linkage rod member (38 or 39) having a knee portion (101), a clevis pin (70) pivotally securing said knee portion (101) to said depending clevis eye means (69), a second clevis pin (61 or 62) pivotally securing the bottom end of said lifting linkage rod (38) to a base post (46 or 47) fixedly secured to said skid member (11), a pusher rod (36 or 37) pivotally secured by clevis pin means (66 or 67) at its top end to said depending clevis eye means (69) of said top slidable travel shoe (68) and at its bottom end by a clevis pin (40 or 41) to an upwardly extending clEvis eye means (34 or 35) of a travel shoe (14 or 15), means (90, 114) slidably retaining said bottom travel shoe (14) in said skid channel member (11), means (89, 111) slidably retaining said skid channel member (11) in said rigid channel member (13), knee-jointed stabilizer legs (42, 43 or 44, 45) pivotally (61 or 62) secured to each said base posts (46 or 47) and to said inverted channel top load-support rail (48), a base post (52) fixed relative to said frame (29), push and pull means (12) operatively biased between said fixed base post (52) and one said skid base post (46) for controllably sliding said skid channel member (11) within said rigid channel member (13), and separate push and pull means (16 or 17) for each lower travel shoe biased thereagainst and against a base abutment (96) fixed relative to said skid 11 for controllably raising, holding and lowering said load-support rail, and skid jack wheel means (18, 19) retractable relative to and extendable below said frame (29) providing mobility for said jack (9).
 2. The skid jack of claim 1, said means for slidably retaining said slidable top and bottom travel shoes and said skid channel member in their respective channel members comprising guide bars (71, 90) secured within said respective channel members (48, 11) and cooperating webs (141 and 111) on said travel shoes (14 and 15) and on said skid channel member (11).
 3. The skid jack of claim 2, said lower travel shoe retainer guide bars (90) within said skid channel member (11) being spaced from the bottom thereof, said skid channel member retainer guide bars (89) within said base channel member (13) being spaced from the inside bottom thereof and said upper travel shoe retainer guide bars (71) being secured to depending side walls from said load support rail (48).
 4. The skid jack of claim 1, said push and pull means comprising hydraulic cylinder (12) and piston means (121).
 5. The skid jack of claim 1, said wheel means including a pair of power receiving wheels (18), a power axle (24) providing rotary power to each wheel, a slip clutch assembly (76) in said power axle (24) providing rotary power to each wheel, a slip clutch assembly (76) in said power axle, and a power motor (74) for said axle.
 6. The skid jack of claim 1, said wheel means including two pairs of forks (20, 21) having wheel mounting axles (22, 23) and wheels (18, 19), said forms (20, 21) being pivoted for retracting or extending said wheels (18, 19), tie means (27) securing said forks (20, 21) together for simultaneous retracting or extending movement, and controllable piston (261) and cylinder (26) means biased between said tie means (27) and said frame (29) for retracting or extending said wheels (18, 19).
 7. The skid jack of claim 6, one pair of wheel forks (121) being vertically pivoted and castored.
 8. The skid jack of claim 7, and latch means (97) for securing said vertically pivoted forks (21) against castoring.
 9. The skid jack of claim 8, and power means (74) operatively connected to one pair of forked wheels (18) providing the powered mobility to said skid jack (9). 